#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main()
{
	int a = 1;
	int sum = 0;
	int ret = 1;
	for (a = 1; a <= 10; a++)
	{
		ret *= a;
		sum += ret;
	}
	printf("%d\n", sum);
	return 0;
}